to be clear, do the Hasselblad FE lenses work on the Contax 645 only in stop-down mode? i guess if you were shooting wide open, there'd be no comproise, but otherwise, you'd have to stop down to meter? if you shot wide open with the 110 FE at f2, do you trust the MAM to be focus-perfect? is the tolerance of manufacture that good? thanks.
Dear Mr., Mrs., Miss, Ms., Dr., Name, or may I call you Phaque?
For the Contax I use the MAM 1 for the blad 100 F2, a zoerk for three pentax, a 165 2.8 a 105 2.4 a 135 macro and a Russian Tilt Shift 45mm
Even the 165 2.8 is in focus to the point you pick the eye you want and it's sharp.
Same with the 100 F2.
Maybe I'm lucky but they all come up sharp and I have used the 100 f2 at 4 to 5.6 and focus was not difficult or seemed that dark.
Then again you need to step back a moment and think about what you would use the converted lenses for. Most of my manual lenses I will use close to wide open anyway, except maybe the 135 for a closeup beauty lens.
I doubt if I would put the blad 100 f2 on to stop down to F11 and if I really want to focus easily I stick with the Contax/Zeiss lenses which I have the range of 35= 3.5, 45 2.8, 80-2, 140-2.8, 210-4.
Like any camera the Contax takes some getting use to, and the viewfinder is not the size of an H-1 maybe in real world viewing not that much larger than a 1ds2, UNTIL you are shooting vertical for U.S. page size.
Then you have a much larger image to focus to as you don't have to pull back across the room to fit the page crop.
The Contax is a real cross over camera. With autofocus and sharp standard lenses it works for commerce quite well. For more esoteric work the ability to add different make lenses is really an advantage.